Magnetic separating device



May 13, 1941. R, H, BUTTERS 2,241,805

MAGNETIC SEPARATING DEVIQE Filed Aprily 15', 1939 y 2 Sheets-Sheet 1 ff/W24,

INVENTOR R. H. BUTTERS MAGNETIC SEPARTING DEVI CE May 13, 1941.

Z'Sheets-Sheet 2 Filed April 15, 1939 Patented May 13, 1941' UNITED STATES PATENT OFFICE 2,241,805 MAGNEro YSEPR'TIG nisv'lc'i: Robert H. Butters, Atlanta, Ga. Application April is, 193'9, serial no. "2er-,99o

2 Claims.

tremely4 hardv and yhencey highlyl destructive,

However, owing primarily to their'speed'of travel and to the small areas which they present to the lsurfaces over which they roll, the separating deT vices heretofore employed have proved ineffective in preventing their passage to Vthe machines to be protected. y A e e 'Ihe principal object of the present invention,

therefore, is to overcome the above objection,

this object contemplating a device 'which is so designed that both poles of the magnetic means exercise simultaneous attractive Vforces upon bearings or other similarly shaped objects which roll upon it, which combination of forces in con junction with the physical characteristics of the deviceinsure arresting and permanent retention of the bearings or other objects regardless of their size or the angle at which the device is arranged without impeding the flow of the material to be processed.

A further object is to provide a self-contained device which requires no outside source of electrical energy and which is capable of retaining its magnetism indefinitely without attention.

A still further object is a novel design and arrangement of the parts of the device whereby compactness and simplicity and economy in construction are obtained.

The invention is illustrated in the accompanying drawings in which:

Figure 1 is a sectional view of a linter having a device embodying the features of the invention associated therewith.

Figure 2 is a horizontal sectional view taken along line 2 2 of Figure 1.

Figures 3, 4 and 5 are fragmentary sections taken along lines 3 3, 4 41and 5 5, respec- L Figure 8 is an enlarged fragmentary sectional view, generally similar to Figure 5, illustrating the manner in which ball bearings of various sizes are engaged by both poles of the magnetic means. e

The invention is illustrated, by way of example, in connection with a cotton seed linting machine, the latterbeing sumciently illustrated for the purpose in View by a showing of the hopper I0, feed roll I I, roll box I2 and angularly inclined wall I3 downvwhich the Dseeds flow by gravity 'fromth'e hopper to the roll box as the feed roll is rotated Yintermittently in accordance with conventionaljpractice. l

The `wall I3 may be of wood, as shown, or of any other suitable material. Preferably it is formed with a shallow horizontally extending recessld in which a pair of bars I5 are secured inspacedrelation b-y screws I6, the depth of the recess I4 being predetermined so that the upper faces f the bars are substantially flush. with, and provide continuations of, the upper face of the wall. The bars extend the full width of the wallfcrosswise of the direction of the flowwof the seeds. In accordance with the invention a division stripv I'I of insulating material is arranged between the bars. The space between the bars is vrelatively narrow and'said strip co-operates with thebars towprvide 0a shallow recess between them, the upper face of the ustrip being inset with respect to the upper faces of the bars a distance which will permit ball bearings of various sizes, and similarly shaped objects, to enter the narrow recess far enough to insure their simultaneous contact with the opposing edges of both of the bars, as best shown in Figure 8, without impeding the ilow of the material to be processed.

A series of openings I8, each of which communicates with the recess I4, is formed in the wall I3. The said openings are preferably uniformly spaced and are adapted to accommodate any desired number of permanent magnets I9, the latter being arranged so that all of their positive terminals contact one of the bars I 5 and all of their negative terminals contact the other bar. The bars, therefore, provide pole pieces of opposite polarity, the strength of the magnetic field which they set up depending, of course, upon the combined strength of the magnets. In order to maintain the stability of magnetic iield thus provided it is preferred that the bars I5 be connected at one or more points by keepers 20. The latter are rectangular in cross section. They flt in elongated slots 2| (Figure '7) formed in the wall I3 between the openings I8; they are located between pairs of the magnets I9 behind the division strip I7; and they are held by attraction against the under faces of the bars. A crosspiece 22, which is secured to the under side of the wall I3, co-operates with the latter, the bars and the division strip, to completely enclose the magnets and keepers.

From the foregoing it will be apparent that all of the cotton seeds delivered to the roll box are rst caused to pass over the bars l5. Hence any metal objects included in the seeds will be attracted by the bars and prevented from entering the roll box. In the event that a ball bearing is included in the seeds its rate of movement will be initially retarded as it rolls over the upper bar toward the slot between the latter and the lower bar. As it partially enters the slot 'and contacts the upper edge of the lowerbarwhilev maintaining contact with the lower edge of the upper bar, it is subjected to the simultaneous attraction of both bars and is arrested. The opposing forces in the magnetic ield are applied substantially equally to the two points of contact and at angles which urge the lbearing into the slot, the mechanical obstruction provided by the edges of the bars increasing substantially the eifectiveness of such forces. y

The use of permanent magnets in the manner described insures permanent retention of the objects separated out of the material to be processed and avoids the necessity of an outside sourcey of electrical energy with its attendant objections. The device has the further advantages that it is compact, self-contained and capable of retaining its effectiveness indefinitely and without attention.

I claim as my invention: n

1. A device for separating vagrant fragments and objects. of metal from a continuously flowing stream of non-magnetic material of granular or fibrous components comprising a board of nonmagnetic material which is set at apredetermined inclination and provides a path along which said stream of material flows by gravity, said board having a shallow recess in its upper face, having openings at determined intervals which extend from said recess to its lower face and having a recess transverse to said shallow refcess in the upper face of one or more of the Webs of material between said openings, permanent CII magnets fitted in said openings with their pole faces substantially flush with the bottom of said shallow recess, a pair of spaced magnetized bars of opposite polarity which are fitted in said shallow recess with their upper faces flush with the surface of said board whereby the non-magnetic material flow-ing along said board will pass rst over one path and then over the other, a keeper tted in said transverse recess below said magnetized bars and held by attraction against the under faces of said bars, and an insulating strip fitted within and closing the space between said bars.

ystream of non-magnetic material of granular or fibrous components comprising a board of non- .magnetic material which is set at a predetermined inclination and provides a path along which said stream of material flows by gravity, said board having a shallow recess in its upper face, having openings at determined intervals which extend from said recess to its lower face and having a recess transverse to said shallow recess in the upper face of one or more of the webs of material between said openings, permanent magnets iitted in said openings with their pole faces substantially flush with the bottom of said shallow recess, a pair of spaced magnetized bars of opposite polarity which are tted in said shallow recess with their upper faces flush with the surface of said board whereby the non-magnetic material flowing along said board will pass first over one path and then over the other, a keeper fitted in said transverse recess below said magnetized bars and held by attraction against the under faces of said bars, and an insulating strip tted within and closing the space between said bars, the relation among said bars and strip being such as to provide a recess of such narrow- Iness and depth that said objects, whenof the structural form and character of ball bearings, will partially enter said recess and therein have contact with the opposing edgesof said bars whereby Vsaid objects will be subject to simultaneously applied opposing magnetic forces and in consequence will be held in said recess against further movement.

` ROBERT H. BUTTERS. 

